中国传统建筑凹曲屋面的挠度假说及其验证（上） ——凹曲屋面的相关假说

The Deflection Hypothesis and Verification On Chinese Traditional Architecture Concave Roof（Part I） ——The Relevant Hypothesis of Concave Roof

摘要:

凹曲屋面是中国传统建筑的主要特征，学者们提出多种假说解释。以曲为美说导向汉民族趣味，易于沦为套套逻辑，加入屋顶厚重的局限条件又会被法国孟莎式屋顶推翻；排水说的史料证据是轮人造车盖——“上尊而宇卑，则吐水疾而霤远”，问题是车盖的断面为弓形，而不是凹曲屋面的人字形。理论解释是最速降线，问题是雨水与瓦片间的粘滞阻力不能忽略，单个雨滴滑落速度优势并不能累加到整个降雨过程，将雨水排离台基依靠回水作法而不是举折作法；采光说符合事实验证，但不是凹曲屋面的决定性因素；反向吸流说不是虹吸现象而是毛细现象，片状空间的反向吸流大大降低；风压说被事实推翻；下滑力不是凹曲屋面的主要原因；乐嘉藻先生最早提出挠度说，但缺乏科学的理论解释和严谨的事实验证。

Abstract:

Concave curved roof is the main feature of Chinese traditional architecture, scholars have put forward a variety of hypotheses. It is easy to be reduced to a set logic, and the limitation of the thick roof will be overthrown by the French mansard roof The historical evidence of drainage theory is the wheel artificial car cover ーー“The superior and the inferior, spits the water to be swift and far away”. The problem is that the viscous resistance between rain water and tile can not be ignored, and the advantage of single droplet sliding speed can not be added to the whole rainfall process The theory of daylighting accords with the facts, but it is not the decisive factor of concave curved roof; the theory of reverse suction is not siphon but capillary phenomenon, and the reverse suction of sheet space is greatly reduced; the theory of wind pressure is overturned by the facts; The sliding force is not the main reason for the concave roof; the deflection theory was first put forward by Mr.